The Inventory and Expenses tab includes the list of inventory items and services that were sold to the customer. If revenue from sale of specific items require recognition during multiple sequential months, you can create deferrals for such items. For items which are sets—a set includes other items as components and selling the set means selling its components according to the specification—you can specify their components by selecting the specifications.
The "Invoice (create)" form. The Inventory and Services tab
To add an inventory item, click the Add or Pick button (refer to Working with the pick operation). In the Item column, select an item from the Items list or create a new item. For more details, refer to Items. Alternatively, you can import the list of items with all the details from an Excel document. For this, click the 
button on the table toolbar and follow the step-by-step instructions in the appeared window. The imported list can be edited in the Administration module.
...
The Characteristic column is available if the Enable Item Characteristics option is selected on the Administration > Settings > Purchasing and Warehouses form. In this column, you can specify additional properties (such as size, color, and so forth) of each listed item if the Use Characteristics option is selected for the item in its master record (see Items).
The Batch column is available, if the Enable Batches option is selected on the Purchasing and Warehouses form. In this column, you can specify the batch (lot) number for the items for which the Use Batches option is selected. Generally, you must specify batch numbers for items with expiration dates, items transferred for consignment or to third-party contract warehouses. To learn more about the item settings, see Settings: Purchasing and Warehouses.
The Serial Numbers column is available if the Use Serial Numbers option is selected on the Administration > Settings > Purchasing and Warehouses form. For each serialized item (for which the Use Serial Numbers check box is selected on the Items form), click in the column to open the Serial numbers dialog box. In this dialog box, you must enter the serial numbers according to quantity of the item.
...
The Set Components button on the table toolbar is available if the Enable Sales of Sets option is selected on the Administration > Settings > Purchasing and Warehouses form). This button is active only for items of the Set type (for details, see Items.) For each item which is a set, you can select the Specification. To view a list of the set components, click the Set Components button on the toolbar - this opens the Set Components dialog box (below in the topic).
In the GL Accounts column, you can view the default accounts to be updated by this transaction. If needed, you can replace them with other accounts.
You can use the Income Item, Expense Item, and Business Activity columns to specify parameters for further analysis of the sales transaction.
...
If the VAT Applied option is selected for this invoice on the Main tab, the VAT, % and VAT Amount columns are available. The VAT amount is calculated in the currency of the document according to the amount and VAT-related settings (which are specified on the Main tab) as follows:
- If the Prices Include VAT option is selected: The VAT amount is extracted from the item amount (Amount), that is,
VAT_Amount = Amount*VAT_Rate/(100+VAT_Rate).
- If the Prices do not Include VAT option is selected: The VAT amount is calculated based on the item amount, that is,
VAT_Amount = Amount*VAT_Rate/100.
...
If you need to create a deferral for any item in the list, select the item and click Create / Cancel Deferral on the toolbar to invoke the Deferred Revenues dialog box (below in the topic). The 
icon in the first column indicates that for this item a deferral was already created. To cancel the deferral, click Create / Cancel Deferral on the toolbar.
The Set Components dialog box
You can use this dialog box to select the specification for an item which is a set.
...